Speed-regulating device



A. GAGG SPEED REGULATING DEVICE Sept. 21 1926.

Filed Dec. 28, 1921 I H. P K 33a Passed Sept. 21,1e2s. I I a 'v UNITED s'TA as PATENT'OFFICE.

' an'ron ease, or znnrcn, swrrznan'ann. srnamnneura'rme Davies;

Application med December as, 1021, Serial no. 525,486,1nd in Switzerland January 11,3921.

The inyention relates to a regulating deand-not on the position of the latter. To vice for governing a servo-motor in which overcome this drawback it has already been device auxiliary means "urge a controlling proposed, as also disclosed in the said member for the servo-motor towards its American Patent No, 1,423 "(86 to provide a mid position, and the device is character a second regulating device of correspondingized by the fact that the action of the auxilly smaller dimensions in addition to the iary means that tend to urge the controlling regulating device acting in the described member towards the mid-position is limited manner, which second re lating device has so as to permit of the member being disfor its tasks to'ensure t e required or de-' placed out of its mid-position by a com arasired dependency of the position of the mov- 55 tively small amount before the auxijary able part of the servo-motor from that of means start to become operative. the pendulum" overnor. The addition of a Regulating devices for governing a servosecond regulatlng device implies of course motor in which a controlling member for the in itself a disadvantage and further thissec 15 servomotor is continuously urged towards 0nd regulating device may give rise to ML the mid-position by the action of auxiliary lations during the. regulating action from means provided to that end, for instance by well known reasons as it is only dependent on. springs or weights, and which controlling the position of the governor. member can only be Zdisplaced out of said T ese disadvantages are overcome by the mid-position by overcoming the resistance device according to the present invention.

of those auxiliary means are disclosed in the A constructional example of the device ac- 'American Patent No.- 1,423,? 86, dated July cording to the invention is shown in the ac- 25,1922. With such know devices the concompanying drawing, in which:

trolling member is displace by the action of Fig. 1 is a diagrammatic view of the coman auxiliary member, for instance a goverplete governing device in which a hydraulinor' sleeve moved by a pendulum governor, cally operated'servo-motor serving to regu-' through the intermediary of a dash pot arlate the speed of a power engine is influenced rangement or the like. The combined action by a centrifugal governor. I

1 of the dash 0t and the auxiliary means act- Fig. 2 illustrates a detail of the governing ing upon t e controlling member ensures means on a larger scale, and

that the controlling member is only dis' Fig. 3 shows diagrams illustrating the placed when and as long as the auxiliary mannerof operation of the regulating demember moved by .the. pendulun'r governor vice. moves at a certain minimum speed and ha Fig. 4 is a modification of a detail.

it is automatically returned into its m1d-' 1 denotes a servo-motor'cyli'nderwithin position as soon as the speed of the auxiliary which a piston 2 is arranged displaceably in means drops below the mentioned minimum the axialdirection. The piston 2 is connect-- as soon as the acceleration of the powerthe servo-motor piston-2 to a main-regulate- '3; Devices of thi si kind effect in a verleadof the pressure to both sides of the piston 2 speed. In consequence thereof every reg ledby means of a piston rod 3 and link! to .lating action is automatically interrupte a lever 5, which transmits the movement of engine dro sbelow a determined-value when ing shaft 6, from which the regulating orthe regulating device is utilized for instance gans'of a power engine, for instance a steam for; governing a servo-motor adapted to con- 2 supply valve, movable guide vanes or the trol a power en like are suitably actuated; The distrlbution vantageous manne an interruptionadf the is governed bya'controlling membenorvalve movement of these o-motor in-the required 7 which is movably arranged within a casand desired moment, but they present the ing 8 and which is provided with notches 40 disadvantagethat by means ofsuch devices along the edges of the periphery. The valve 'a determined position of the movable part 7 forms the controlling member forthe servoof the servo-motor is not attained without motor 1, 2. Tothe'casmg 8 liquid under any further mechanism, as the action'upon pres ure is su phed by a conduit 9, the the servo-motor is solely dependent on the branches 10 an 11 serving for the discharge speed of the movement...o f the auxiliary ofcthe pressure liquid.- In the casing'8hanm I fili a; f9? e e vanular channels 12 and 13 are provided w ic valve 7 3o are connected by means of the conduits 14 and 15 with the spaces 1 and 1 respectively of the cylinder 1.3 The controlling valve 7 is rigidly connected by means of a the casing 17 of a dash pot, the piston 18 of which is linked by means of a rod 19 to the outer end-2O of a regulating lever 21, which is adapted to turn about the fixed fulcrum. pin 22, the turning motion being efi'ected bythe intermediary of a sleeve 24 of a centrifugal governor 25. The latter is rotated in a known manner, not shown in the drawing, by the power engine.

The connecting rod 16 is provided with a reduced part 26 (Fig. 2) which is limited at either-end by the facings 27 and 28 act-- ing as-stops. On the part 26 two discs 30 and 31 are provided between which a helicgl spring 32 is arranged. The action of t is be ordinarily pressed against the faces 33 and 34'of the casing '8 of thecontrolling valve. In the mid-position of the controlling valve 7 present, between the stop 27 and the disc 30 on the one hand and between the stop 28.

and the disc 31: onthe other hand, by the amount of which clearance the regulating can be moved in the. upward and downward direction without it being necessary to overcome any resistance of the spring 32. Inside the dash-pot casing 17 springs 41 and 43 are provided which bear with their'one end on the upper and lower end part respectively of the casing 17 and with their other end on the rings 35 and 36 respectively. The rings 35 and 36 rest, when the piston 18 is in its mid-position withregard to the casing 17, on stop faces 42 formed by the middle portion of .the casing 17 which portion is of smaller. inside diameter than the other parts of the easing, so that the piston 18 of the :dash pot is 'held in thementioned mid-position with regard to thecasing,17. The pressure of the springs 41 and 43 is somewhat smaller thanthat of spring 32. The dash-pot piston 18 is' provided with a small bore, 37 through which the liquid contained in the dash-pot may pass piston 18 to the other.

The operation of the above described device will now be explained with reference to the accompanying 5 gram in Fig." 3 of this drawing the abscissae measured from left to right represent the time t of the regulating action and the ordinates represent firstly the admission openi g o of the mainsupply organ of.the'pow-- e engine and secondly the-number of-revolutions n of this engine. Let it be assumed that up to the time t, a state of persistence is present, the ad'- or repose of the engine mam supply organ mission opening of the being a and the speed 02 rod 16 with spring 32 causes the discs 30 and 31 to a small clearance (Fig. 2) is y from one side of the drawings. In the dia At the time i,"

upon load being taken off the engine. In

consequence thereof an acceleration of the engineinstant ly occurs. Therefore the, sleeve 24 of the centrifugal governor 25 is raised causing the lever-21 to'beraised and to turn about its fulcrum pin 22. At the beginning of the upward vmovement of the lever 21, when the dash-potpiston is caused to take part in said movement by the rod 19, the dash-pot casing 17 together with the controlling piston-7 connected thereto is also raised in consequence of the tensionimparted to the upper spring 41 in the dash-pot. .However as soon as the stop 28 comes to rest against the disc 31 a -furv ther' movement of the controlling piston 7 overcoming the pressure of'the spring 32,

i. e. when a liquid pressure is present above casing 17. The higher this speed is,. the

higher is of course the pressure that is. required in order to force the liquid to be dis placed in the dash-pot through the bore 37 of the piston 18. As soon as the velocity with which the piston 18 moves in the upward direction drops-below a determined degree thepressure above the piston 18 will become so small that the controlling piston 7 is urged in the downward direction i. e. towards its mid-position by the influence of the spring 32. a By suitably choosing the spring pressures and-the diameter of the bore 37 in -'the piston 18 the urging back of the controlling piston may be effected atthe desired moment. Advantageously the ratios are so chosen that the controllingpiston, 7 remains wholly displaced; from the time t, to'the time t (Fig. 3) and that at'a proximately the time t at which the spec of the upward movement of the piston '18 has alf eady substantially decreased, the controlmg that it isagain approximately in its midposition when the culminating point a of the time it On; account of the regulating 1n the upward direction ca'nonly occur by action described pressure liquid has been supplied to servo-motorl, i. .e. to the space 1, during the interval between the time t, to t whilst. the space 1 charge during said interval. quence thereof the piston 2 has been displaced from right to left and has thereby decreased the admission opening of the main supply member of the engine f10ln0 has been connected to the dis- In conse the right-hand portion of the to At the time i, no acceleration of the engine takes place and t e engine runs at least under certain con itions with the proper admission corresponding to the new load, but the number of revolutions n of the engine is still too high at that moment.

As has been explained above, the controlling igalve 7 has returned in a downward direction by the action of the spring 32 when the acceleration of the engine has ceased and the quick movement of the piston 2 towards the left has been interrupted. However, the controlling valve 7 returns in that downward direction under the influence of the spring 32 only so faruntil the disc 31 comes to rest against the stop lacing 34 of the casing 8. The controlling valve 7 then remains under the influence of the compressor upper spring 41 in the dash-pot 17, 18 displaced in the upward direction by the small amount of the-clearance that is present between the face 28 of the connecting rod 16 andthe disc 31 when the controlling valve is in its mid-position. Thereby the notches provided at the edge of the controlling valve are still in action and the piston 2 is slowly moved further to the left to further decrease the admission of the engine. In consequence thereof a decrease of the speed results thereby, in the manner disclosed in the American Patent No. 1,180,583 shortly after the culminating point a, of the n curve is passed, for instance at the time t the controlling valve 7 is also returned by the small amount by which it was still displaced in the upward direction after its return movement under the influence of the spring 32, i. e. it is returned into its midosition, whereby the complete interruptlon ofthe closing movement of the piston 2 is effected.

If'the speed of the engine decreases owing to an increase in the load, the respective regulating action takes place in the reversed manner.

The regulating device may be subjected to constructional modifications without altering the nature of the invention. In this way, for instance, as is shown in Fig. 4, a separate spring and 51 respectively acts upon each disc 30 and 31, in which case a member 52 rigidly connected to the connecting'rod 16 isinterposed between said discs.

' The main regulating shaft 6 may of course influence any organs, for instance organs adapted to'damp the oscillating movements of parts such as rolling movements of servomotor, auxiliary means which are independent of the movement of the servomotor piston and which tend to urge the controlling member into its mid-position, means operatively connecting said member to said auxiliary member and adapted to effect, while influencing said auxiliary means, a displacement of said controlling member out of its mid-position as soon as the velocity with which the auxiliary member is moved in one or the other direction exceeds a certain limit, and being further adapted to keep saidcoiitrolling member out of its mid-position as long as said velocity is exceeded, and means to limit the action of said auxiliary means so as to permit the cdn-, trolling member to be displaced. out of its mid-position by a comparatively small amount before the auxiliary means acts on said controlling member.

2. A- governing device for servo-motors, comprising an auxiliary member the position of which is dependent on the working conditions to be regulated, a member for controlling controlling the movement of a piston of the long as the velocity is exceeded, and means to limit the action of said spring so as to permit the controlling member to be displaced out of its mid-position by a comparw .tively small amount before the spring acts on said controlling member.

3. A governing device for servomotors, comprising an auxiliary member the position of which is dependent on the working conditions to be regulated, a casing, a controlling piston for the servomotor, the piston being movable in said casing and provided with notches along the edges, a spring adapted to act upon said'controlling piston independently of the movement of the servomotor piston and which spring tends to urge said controlling piston into its mid-position, means operatively connecting said controlling piston to said auxiliary member and adapted to efiect while influencing said spring a displacement of said controlling plston out of itsmid-position as soon as the velocity with which the auxiliary member ismoved in one or the other direction exceeds a certain limit, and being further adapted to kee said controlling piston out of its mid-- positionas long as said velocity isjexceeded,

the controlling piston being freely movable movement of the valve with respect to said 1 for a comparatively small amount out of its spring, and means operatively connecting mid-position before said spring acts on it. the valve and governor to compress sai 4. A governing device for servomotors, spring after the independent movement has comprisinga governor controlled by the -ma been effected, the valve and its associated chine served by the servomotor, a valve casparts being free of mechanical connection 1 ing for the servomotor, a piston valve in with the operating parts of the servomotor. said casing, a spring controlling said valve In testimony vvhereof I aflix my signature. and means to permit hmited independent i ANTON GAGG. 

